Global Patent Index - EP 1048387 A2

EP 1048387 A2 2000-11-02 - Method of cutting a workpiece along an arcuate path with a plasma arc torch

Title (en)

Method of cutting a workpiece along an arcuate path with a plasma arc torch

Title (de)

Verfahren zum Schneiden eines Werkstücks in einer bogenförmigen Bahn mit einem Plasmalichtbogenbrenner

Title (fr)

Procédé de coupage d'une pièce suivant une trajectoire curviligne avec une torche à l'arc au plasma

Publication

EP 1048387 A2 (EN)

Application

EP 00302588 A

Priority

US 30177799 A

Abstract (en)

A method of cutting a workpiece along a cutting path that is arcuate or that has one or more arcuate portions includes the step of determining a control parameter that is proportional to the angular velocity of the torch. The arc current supplied to the torch is regulated based on the control parameter and the linear advance rate of the torch, which in turn is a function of the material type and thickness of the workpiece. In one embodiment of the invention suitable for the cutting of holes, the control parameter is the diameter of the hole to be cut, which for a specified linear advance rate is inversely proportional to the angular velocity of the torch. The current is increased above a nominal current when the hole diameter is less than or equal to a predetermined limiting diameter, and otherwise is set at the nominal current. In other embodiments of the invention suitable for cutting holes or other shapes, the control parameter is the radius of curvature of the cutting path. Alternatively, the angular velocity can be used as the control parameter. Increasing the current at higher angular velocities and/or when cutting holes of small diameter tends to reduce the problem of the arc not following the desired cutting path and creating cut surfaces that do not conform to the desired cut surfaces.

IPC 1-7 (main, further and additional classification)

B23K 10/00

IPC 8 full level (invention and additional information)

B23K 10/00 (2006.01)

CPC (invention and additional information)

B23K 10/00 (2013.01)

Designated contracting state (EPC)

AT DE DK FI FR IT

EPO simple patent family

EP 1048387 A2 20001102; EP 1048387 A3 20021113; AU 3015300 A 20001102; AU 759759 B2 20030501; CA 2302880 A1 20001029; CA 2302880 C 20040921; JP 2000317640 A 20001121; JP 3249501 B2 20020121; MX PA00004213 A 20020308; US 6153850 A 20001128; US 6274842 B1 20010814

INPADOC legal status


2005-04-06 [18D] DEEMED TO BE WITHDRAWN

- Effective date: 20040903

2003-10-15 [17Q] FIRST EXAMINATION REPORT

- Effective date: 20030901

2003-07-30 [AKX] PAYMENT OF DESIGNATION FEES

- Designated State(s): AT DE DK FI FR IT

2003-05-07 [17P] REQUEST FOR EXAMINATION FILED

- Effective date: 20030311

2002-11-13 [AK] DESIGNATED CONTRACTING STATES:

- Kind Code of Ref Document: A3

- Designated State(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

2002-11-13 [AX] REQUEST FOR EXTENSION OF THE EUROPEAN PATENT TO

- Free text: AL;LT;LV;MK;RO;SI

2002-11-13 [RIC1] CLASSIFICATION (CORRECTION)

- Free text: 7B 23K 10/00 A, 7B 23K 9/095 B, 7B 23K 9/013 B, 7H 05H 1/36 B

2000-11-02 [AK] DESIGNATED CONTRACTING STATES:

- Kind Code of Ref Document: A2

- Designated State(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

2000-11-02 [AX] REQUEST FOR EXTENSION OF THE EUROPEAN PATENT TO

- Free text: AL;LT;LV;MK;RO;SI